Suspended structures and assemblies such as linear lighting fixtures (a lighting fixture is also often referred to as a luminaire) are commonly used for the illumination of open spaces due to their ease of installation and their flexibility to be able to be configured to simultaneously provide many different combinations of direct and indirect light in a wide variety of form factors and optional features.
Linear lighting fixtures may be suspended from a ceiling or building support structure using a plurality of suspension means, such as a fixed or adjustable wire cable hangar, a pendant pipe, a chain, or other type of hangar, typically at or near each end of the fixture. Sometimes additional suspension means are added to a fixture, a linear array, or combination of fixtures to prevent sagging or bowing due to gravitational forces, which typically occurs either in the middle of the array or fixture if only an outer pair of suspension points is used, or more generally, at or near the midpoint between the suspension points. It is advantageous to minimize the quantity of suspension means used in such a system, in order to save installation cost and time, and to improve aesthetic appeal. However, sufficient structural support must be present in order to eliminate any sagging of the fixture(s). While structural integrity of the fixture is critical, customers often deem fixtures that sag as a less than attractive look to the lighting system, which diminishes the aesthetic appeal of the lighting system. If the lighting system is not sufficiently structurally supported, and since lighting fixtures can have relatively heavy metal housings which include the light source(s) and electrical components such as ballast systems, an insufficiently supported lighting system can be a safety concern since such a system can potentially fall from the ceiling and a falling fixture is a hazard to people and/or property.
One possible solution to improving the structural integrity of a suspended assembly is by a brute force approach of increasing the thickness of the material used in the walls of the housing of the assembly, but depending on variables such as the overall length of the fixture, this approach may not necessarily achieve the desired results without also increasing the overall dimensions of the assembly. Even if it were successful, this approach is more costly both for materials and shipping, the parts are more difficult to handle in manufacturing, and installation is more difficult.
Another solution to ensuring the structural integrity of a longer assembly such as a lighting fixture is shown in Lanczy, in U.S. Patent Application No. 2006/0158877, which describes a joiner assembly for joining and supporting two linear lighting fixtures together. The joiner assembly includes a joiner bracket including first control surface connected to a second control surface and a draw fastener hole therebetween. The first control surface is configured for controlling a position of the first linear lighting fixture in a prestressed condition, and the second control surface is configured for controlling a position of the second linear lighting fixture in a prestressed condition. A draw fastener is connected to the draw fastener hole. A draw fastener constraint is connected to the draw fastener and configured for connection to at least one of the first linear lighting fixture and the second linear lighting fixture. Due to the visual presence of the break line between fixtures, and the fact that the prestressing is accomplished with linear segments instead of curved or arched ones, this approach makes the break line more pronounced.
It would be highly desirable to have a suspended assembly such as a linear lighting fixture/luminaire that would have the characteristic of preventing sagging or drooping inherent in the assembly itself.
It is therefore an object of the invention to enhance the suspendable assembly art.
It is another object of the invention to incorporate prestressing, at least along a major longitudinal axis, into at least a portion of one of the components in a first structure, such as a luminaire, that is intended to be suspended from a second structure, such as a ceiling to accomplish particular design objectives.
It is still another object of the invention to provide a lighting fixture/luminaire that is both structurally stronger and more aesthetically pleasing.
It is an additional object of the invention to provide a lighting fixture/luminaire with reduced weight, improved manufacturability, lower cost, easier installation, and improved aesthetic appeal.
It is yet another objective of the invention to provide a plurality of lighting fixtures/luminaires, each comprising a structural member with prestressing, that when attached together and the overall structure is suspended, provides the objectives and benefits described hereinabove.